Systems for performing highly accelerated life testing (HALT), highly accelerated stress screening (HASS), and highly accelerated stress audits (HASA) are available to test the reliability and durability of manufactured products. More particularly, the durability of products can be tested using HALT systems and procedures. Products can also be tested for defects before they are distributed to consumers using HASS procedures, where all of the products are tested, or HASA procedures, in which samples taken from a production run are tested. In general, such testing includes subjecting devices under test to vibration energy and/or temperature cycling. Such stresses may be introduced to a device under test by mounting the device under test to a shaker or vibration table that is located inside an environmentally controlled test chamber.
Particularly in connection with HASS and HASA programs, including HASS and HASA programs that utilize multiaxis random vibration combined with rapid (greater than 40 C per minute) changes, it is desirable to provide systems that are capable of efficiently testing a large number of devices. To this end, test chambers are available that allow vibration tables to be accessed from multiple sides, facilitating the placement of devices under test in the test chamber, and the interconnection of the devices under test to the vibration table. However, particularly with vibration tables having a relatively large area, there is often at least a portion of the vibration table surface that is difficult to access, and that is therefore rarely if ever used to support a device under test. Accordingly, the maximum available throughput of the test chamber is not utilized. The result is that the cost per unit tested is higher than it would otherwise be. In addition, where a relatively large vibration table surface is provided and/or where at least a portion of the vibration table surface is unutilized or underutilized, the volume of the test chamber is larger than would otherwise be required. This results in a system that uses more energy to effect thermal cycling of the chamber than might otherwise be required.
A single table with a relatively large area can also be inconvenient, particularly where a number of devices under test are to be connected to the table.